Database software often writes data in units called pages. In certain embodiments, the size of such a page may be chosen by a user. Using DB2 for example, page sizes range from 4 kilobytes to 32 kilobytes. Generally, the larger the page size, the better the performance of the database program.
When storing database files, or copying database files in a PPRC operation, the write of a page can fail at any point in the write operation due to, among other things, a server failure, server power failure, network failure, switch failure, storage device failure, and the like. As a general matter, storage operations will maintain the atomicity of a write operation if the write data is contained within a single “track.” However, if a write or copy operation crosses a data storage medium track boundary, there is no guarantee that atomicity of the write will be maintained, i.e. a portion of a database page may be received and stored and another portion of that same database page may be lost.